Edit report at http://bugs.php.net/bug.php?id=51622&edit=1

 ID:          51622
 Comment by:  andrewm dot finewolf at gmail dot com
 Reported by: oliver dot graetz at gmx dot de
 Summary:     ArrayObject::offsetGet should return a reference
 Status:      Open
 Type:        Feature/Change Request
 Package:     SPL related
 PHP Version: 5.2.13

 New Comment:

Arrays in PHP contains references to primitive types and reference
types. Which basically means that if you are post-incrementing an
element, well, it actually works.



Why is ArrayAccess::offsetGet() returns by value instead of by
reference? Wasn't ArrayAccess created to emulate an array? This is a
major inconsistency in the platform and makes this whole interface
pretty useless. This isn't an engine limitation. __get(), __set(),
__isset(), __unset() is returning values by reference without any
problems. Why can't ArrayAccess (when it does pretty much the same
thing?)



Can ArrayAccess::offsetGet() return by reference (or at the very least
create a second interface, "ArrayAccessRef", for this)?


Previous Comments:
------------------------------------------------------------------------
[2010-04-27 10:02:34] col...@php.net

This is actually a feature request. To be backward compatible, we would
need to 

have a new interface, and obviously a new interface only to solve that
reference 

thing is painful.



The immediate solution is to return an ArrayObject itself, which means
that 

indirect modifications will work.

------------------------------------------------------------------------
[2010-04-21 13:35:50] oliver dot graetz at gmx dot de

Description:
------------
This bug refers to my report filed under
http://bugs.php.net/bug.php?id=34783 which is now more than four years
old. In the meantime I found out that using ArrayObject instead of the
test class the



    $t['huba'][]='three';



actually works, thanks to the SPL using its "implemented in C advantage"
to circumvent the problem. Actually, it works until the programmer
decides to inherit from ArrayObject and overwrite offsetGet(). Then the
problem of the offsetGet() method not returning by reference is back.



Back in 2005 you were very quick to flag the report as BOGUS, but a look
at the source code of "zend_interfaces.c" proves that there is in fact a
problem:



ZEND_BEGIN_ARG_INFO_EX(arginfo_arrayaccess_offset_get, 0, 0, 1) /*
actually this should be return by ref but atm cannot be */



The best way of dealing with this is not to mark it as BOGUS and deny
that there is a problem. It would be admitting the fault and perhaps
introducing an alternative NewArrayAccess interface that defines
&offsetGet(). So future code can use it without breaking old
implementations.



Test script:
---------------
<?php

class Test1 extends ArrayObject

{

}

class Test2 extends ArrayObject

{

        function offsetGet($key) { return parent::offsetGet($key); }

}



$t1           = new Test1();

$t1['huba']   = array('one','two');

$t1['huba'][] = 'three';

print_r($t1);



$t2           = new Test2();

$t2['huba']   = array('one','two');

$t2['huba'][] = 'three';

print_r($t2);



Expected result:
----------------
Test1 Object

(

    [huba] => Array

        (

            [0] => one

            [1] => two

            [2] => three

        )



)



Test2 Object

(

    [huba] => Array

        (

            [0] => one

            [1] => two

            [2] => three

        )



)

Actual result:
--------------
Test1 Object

(

    [huba] => Array

        (

            [0] => one

            [1] => two

            [2] => three

        )



)



Notice: Indirect modification of overloaded element of Test2 has no
effect in F:\huba.php on line 17

Test2 Object

(

    [huba] => Array

        (

            [0] => one

            [1] => two

        )



)


------------------------------------------------------------------------



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